Lin Yumeng adopts the foolish Peng Zhan, and the sister and brother depend on each other in the marketplace. To cure Peng Zhan's mental illness, the two mistakenly enter Mount Baihu. Peng Zhan is plotted against by villains and falls into the Demon Locking Cave, but unexpectedly obtains the inheritance of Lingxiao Palace, recovers his sanity, and masters extraordinary skills and medical arts. Upon returning to the marketplace, he protects his family with his abilities, punishes dark and evil forces, rescues women, and helps neighbors with medical skills. From an ignorant fool to a responsible protector, he stays true to his original aspiration, punishes evil and promotes good with his own strength, guarding the warmth and justice of the world around him.